A person may contract hernia if the abdominal wall has a weak area that is not capable of keeping the peritoneum in place when larger pressures occur in the abdominal cavity. When hernia occurs, a bulge on the peritoneum, the so-called hernial sac, has penetrated through an opening, called hernial ring, in the abdominal wall and into the hernial canal. In herniotomy (herniotomia) the hernial sac is passed out of the hernial canal and away from the hernial ring. In order to prevent recurrent hernia the abdominal wall may then be strengthened on a level with the hernial ring.
This strengthening has traditionally been effected by stitching a piece of tissue across the hernial ring. In recent surgery methods the herniotomy is effected percutaneously by means of an endoscope and one or more working channels, thereby avoiding proper cutting through the abdominal wall. It is a prerequisite of this technique that all of the objects necessary for the operation can be inserted in the abdominal cavity and manipulated intraperitoneally through comparatively thin tubes. The working channels may be established by cutting with a scalpel a small hole through the abdominal wall and inserting a tube in the hole. Alternatively a trocar may be used, in which case the working channel is delimited by a trocar sheath. For the sake of simplicity the working channel is hereinafter referred to as a trocar sheath.
From the article, "Improvement in Endoscopic Hernioplasty," from Journal of Laparoendoscopic Surgery, Volume 1, No. 2, 1991, it is known to make two incisions through the peritoneum on a level with the hernial ring and to pull a barrier material in the form of a synthetic patch through one incision and spread the patch over the hernial ring by means of gripper pincers, following which the two incisions in the abdominal wall are sutured.
From the conference, Advanced Laparoscopic Surgery: The International Experience, held in Indianapolis, U.S.A., in the period from 20 to 22 May 1991, a supporting device of the above mentioned type was referred to by Dr. John Corbitt in his Paper on "Repair Indirect Inguinal Hernia at Laparoscopy." After removal of the hernial sac John Corbitt fills up the hernial canal with a plug of rolled gauze, following which the hernial ring is closed by means of a net patch which by means of pincers are spread across the hernial ring and fixed to the abdominal wall by means of plastic or metal clips. Another lecturer at the conference, Dr. Maurice Arregui, practices a similar technique while positionally fixing the mesh patch at the hernial ring by suture.
It is a drawback of the above surgical methods that barrier material inserted through the trocar has to be spread manually across the hernial ring and fixed manually, as this manipulation is very time-consuming. When the net is positionally fixed by suture, the patient must still keep his bed after operation for 3 to 4 days in order to ensure healing.
When laparoscopy is used in the diagnostic or surgical treatment of a patient one or more trocar sheaths are inserted through the abdominal wall and the necessary equipments, such as a light source, a viewing telescope and surgical instruments, are passed into the abdominal cavity and manipulated through the trocar sheaths. However, the trocar sheaths may create weak areas in the abdominal wall due to their penetrating the wall and creating openings therein.